AUTHENTICATION DEVICE AND AUTHENTICATION METHOD

PROBLEM TO BE SOLVED: To attain individual authentication of high accuracy even if the amount of incident light, atmospheric temperature, body temperature and the way to put fingers change. SOLUTION: This authentication device comprises a light source for irradiating the fingers with infrared light; an imaging means 8 imaging with transmitted light and outputting an image signal; a low frequency luminance component extracting means 61 extracting a low frequency luminance component signal from the image signal; a medium frequency luminance component extracting means 62 extracting a medium frequency luminance component signal from the image signal; a correcting means 63 correcting the medium frequency luminance component signal using the low frequency luminance component signal; a quarternarizing means 64 for quarternarizing the corrected medium frequency luminance component signal so that quarternary distribution is a predetermined ratio; a storage means 7 for storing a quarternarized image; a correlation coefficient computing means 65 computing a correlation coefficient of an evaluation quarternarized image for evaluation and a registered quarternarized image stored beforehand in the storage means, using a pattern matching method based on a normalization correlation method; and a determining means 66 determining whether the evaluation quarternarized image and the registered quarternarized image are the images obtained by imaging the same fingers based on the correlation coefficient. COPYRIGHT: (C)2009,JPO&INPIT